MVVM Datagrid与通用类型的Observable Collection绑定

Question

I have a xaml UserControl in which the DataContext refers to a "Control"-ViewModel.

mc:Ignorable="d" d:DataContext="{d:DesignInstance controls:ControlViewModel}"

Furthermore, I´ve binded the ItemsSource to an ObservableCollection which is generic from a "Data"-ViewModel. (Please Note: these data are only for demonstration)

    <DataGrid ItemsSource="{Binding DataCollection}" SelectedItem="{Binding SelectedData}">
        <DataGrid.Columns>
            <DataGridTextColumn Header="Name" Binding="{Binding Name}"/>
            <DataGridTextColumn Header="Age" Visibility="{Binding AgeVisibility}"  Binding="{Binding Age}"/>
        </DataGrid.Columns>
    </DataGrid>

public class ControlViewModel
{
        private ObservableCollection<DataViewModel> _dataViewModels;
        public ObservableCollection<DataViewModel> DataViewModels
        {
            get { return _dataViewModels; }
            set
            {
                   _dataViewModels = value;
                    RaisePropertyChanged("DataViewModels");
            }
        }
}

The "Data"-ViewModel has the following Properties, which I´ve binded to the specific DataGridTextColumn (as you can see).

public class DataViewModel
{
        private string _name;
        public string Name
        {
            get { return _name; }
            set
            {
                _name = value;
                RaisePropertyChanged("Name");
            }
        }

        private int _age;
        public int Age
        {
            get { return _age; }
            set
            {
                _age = value;
                RaisePropertyChanged("Age");
            }
        }

        private Visibility _ageVisibility;
        public Visibility AgeVisibility
        {
            get { return _ageVisibility; }
        }
}

Everything works, expect that the Visibilty Property of the "Age" Column doesn´t easily refer to the generic DataViewModel (Properties) of the Observable Collection such as the Binding Property. So it cannot be solved and it´s always on it´s default.

Answer 1

If you want a bindable property then add a second RaisePropertyChanged to the properties that control the readonly property.

public class DataViewModel
{
    //other stuff

    private int _age;
    public int Age
    {
        get { return _age; }
        set
        {
            _age = value;
            RaisePropertyChanged("Age");
            RaisePropertyChanged("AgeVisibility");
        }
    }

    public Visibility AgeVisibility
    {
        get { return this.Age > 0 ? Visibility.Visible : Visibility.Hidden; }
    }
}

You can also use type converters like this